Recirculating stabilizer pump



Jan. 1, 1946. T. R. nlNsMoRE RECIRCULATING STABILIZER Y PUMP Filed Aug. '7, 1944 catia,

N EN j Teoaare E Dz'rzsmare Patented Jan. 1,

BECIRCULATING STABILIZEB Theodore lut. Dlnsmore, Dayton, Ohio, assignor to Curtis Pump'Com'pany, Dayton, Ohio, a corporation of h10 Application August 7, 1944, Serial No. 548,345

This invention relates to pump devices which separate vapors from liquids and repeatedly treat liquids before they are pumped to insure delivery of fully liquid material.

Specifically, the invention deals with a fuel reclrculator attachment for a booster pump of an airplane fuel system.

In accordance with this invention, a vapor and liquid separating booster pump is mounted in the fuel tank of an airplane to be submerged in fuel,

in the t The pump is equipped with centrifugal pumping varies and amai how vanes t0 circulate bubble-rich liquid out of the so that the centrifugal pumping vanes will not become gas-bound. An axial iiow stream of fuel is created locally in the tank and this Stream is denected to new back to the pump. Bubbles entrained in the stream are permitted to rise in the d of fuel in the for bursting at the sur@ face of the pond to liberate the ges vapors therefrom. The fuel, including recirculated fuel, is screened before it' can reach the inlet of the pump, so that any secluded bubbles are prevented from passing hack to the pump with the liquid.

Since the tank is vented to the atmosphere, and c ge the liberated' gases and vapors out ofthe ank vent, continued treatment or' the liquid fuel in the tank by the vapor separating pump rey suits in the creation of a stabilized fuel freed from .vapors produced hy volatiles which gasifv at rareded high altitude atmospheres. The continnedrecircuiation and repeated agitation ci the iuel hy the pp thus produces locally in the s 'n a stabilized uei which is eventually pumped into the fuel line or' the fuel system. Vapor lock in the iuel system is thereby eted since only a stabilized, vapor and gas-freed, liquid fuel is delivered into lthe fuel line.

It is, then, an'object of this invention to provide a pump assembly .which subjects liquid to a plurality of vapor-separating operations before ypumping the liquid.

A further obiect of the invention is to provide a p which-stabilizes volatile liquid material' before pumping it. I v

Another object of the invention is to provide a booster pump especially adapted for airplane fuel systems which stabilizes liquid fuel by repeatedly agita the fuel before pumping it.

A still further object of the invention is to recirculate fuel in a tank through a vapor-separat- -ing pump for stabilizing the fuel.

Another object of the invention is to equip a vapor-sept boosterpump with a recirculatample only, illustrates one embodiment ofthe inlfollowing detailed description of the annexed i sheet of drawings which, by way of preferred exvention.

On the drawing: l

Figure 1 is a broken fragmentary vertical crosssectional view with parts in elevation, of a booster pump according to this invention mounted in a fuel tank.

Figure 2 is a horizontal vcross-sectional view, with parts in plan, taken along the line II-II of Figure l.

Figure 3 is a plan view of the deiiector shield, of the pump, and showing a Part in horizontal cross section.

As shown on the drawing:

In Figure l, the reference numeral i@ designates generally a tank such as an airplane fuel tank.

The tank l contains a pond P of liquid fuel such as gasoline or other volatile liquid.

The tank lhas a .bottom wall il apertured as I at Ha and receiving thereon around the aperture i la thereof a mounting ring I2. l

A pump and motor unit i3 has a base le mount ed on the outside of the tank bottom lwall il toV 'cover the aperture Ha thereof. IThis base iii receives cap screws it therethrough at spaced in tervals therearound. These cap v screws are threaded into the mounting ring I2 to suspend the unit i3 in the tank.

As shown ih Figure 1, the base it has an aperture therethrough closed by a bottom cap it. The

cap it is secured to the base it by means of cap screws il. A drain plug IS is provided in the cap it. A gasket such as I9 isinterposed between the base It and the cap I6. An additional gasket (not shown)` can be interposed between the tank wall' Il and the base Il.

The apertured base plate it andthe cap i6 cooperate to denne a sump S beneath the bottcm Il of the tank I0.

The base I4 has an'upstanding open ended tubular portion 20 integral therewith and projecting into the tank lil. This tubular portion 20 receives a. conduit ttingl-on the bottom end thereof together with a cap 22 on the top end thereof. A single bolt 23 is passed through the :ltting 2| and is threaded into the cap 22 to securel the cap and tting to the end'of the "tubular portion 2E. The cap and tting areinterchangeable so that the passageway 20o pro vided by the tubular portion zu een discharge s into an inside tank fitting oran outside tank ilttingas shown.

in Figure 1. 'I'he head 29 supports a motor casing 29 in which is mounted an electric motor having an amature rotating a drive shaft 21. The drive shaft 21 projects through a collar p0rtion 25a of the head. A stationary seal ring 29 is mounted in this collar portion 23 and cooperates with a rotating seal ring 29 driven by the shaft 21 to seal the motor in the casin'g 26 from liquid of the pond P. As shown, the rotating seal ring 29 has a rubber sleeve 39 clamped therearound by means of a metal cap 3| and this rubber sleeve is held on the shaft by means of a ring or hoop 32. 'I'he rubber ring preventsleakage along the shaft through the rotating seal ring 29. 'I'he cap 3i is driven through a keyed connection 33 with a member held on the shaft. A spring 34 urges the rotating ring 29 into sliding face engagement with the stationary ring 29.

A leg 35 depends from the head 25. A volute ring 36 is integral with the bottom end of the leg 35 and has ribbed connection with the base plate 1 4 as at 31. A tubular portion 39 connects the volute ring with the upstanding tubular portion 20. This portion 38 is hollow and serves as a passageway for conducting fluid from the volute chamber 39 of the ring 36 to the passageway 20a in the tubular portion 23.

The ring 36 has an open bottom endabove the cap I6 receiving a throat ring 40 therein. Cap screws such 4-as 4l secure the throat ring A to the volute ring'.

A pump impeller, indicated generally by the reference numeral 4I, is mounted in the volute asesinas tne'eereen disk u te the les al. A eminemnectionis made by an angle bracket I3 and a screw 34toabossi3onthevolutering34.

The screen disk 44 does not overlie the axial flow vanes 43.

A deilector shield 54,-best shown in Figures 1 and 3. ts snugly around the collar portion 23a ofthe head 25 and is suspended from the head by means of 'a leg 51. .Notches I3 are cut into the periphery of the shield member Il to straddle the ribs 24. The shield can be soldered or otherwise seeuredto these ribs if desired.

ring. This impeller 4l includes a hub 42 secured on the bottom. end of the shaft 21. This hub is joined through helical'axial flow-producing vanes 43 with 'a collar member 44 riding in the upper end of the throat ring 36. The collar member 44 ha's an outturned flange 44a at'the botto`m end thereof from which' depends a plurality of spaced centrifugal pumping vanes 4I.

The pumping vanes 4B extend downwardly tothe inlet opening 49a of the throat ring 49 and have radially extending portions communicating with the volute chamber 39 of the ring 39.

The impeller 44i thus cooperates with the volute ring 33 and the throat ring 40 to provide a central chamber through the pump with the lower end of the chamber in full open communication with the sump S, and with the top of the chamber having the Tvanes 43 therein to create an axial ow through the chamber. The vanes 43 are pitched to induce axial flow through the chamber. The. vanes 45 are curved for centrifugal discharge from the axial ilow chamber into the volute chamber 39. vLiquid under pressure in the volute chamber 39 is flowed through thetubular'portion 38 into the passageway 20a from which 1t is discharged through the conduit iltting 2i to the fuel line of the airplane fuel system.

As shown in Figures l and 2, a cylindrical screen 41 is bottomed on the base plate I4 and extends upwardly therefrom above'the level of I the volute ring 36. The upper end of the cylindrical screen 41 iscovered with a flat screen disk 48 which is secured to the screen 41 by means of angle brackets 49 and screws 50 at spaced intervals therearound. As shown, an angle bracket Il and screw l2 connect the inner portion of y As shown in Figure 3, the shield is in the form of a dished disk which, as indicated in Figure 1, provides an umbrella-like deilector in spaced relation abovethe axial flow vanes 43 and the screen disk 43,

In operation of the unit i3, the motor in the casing. drives the shaft 21 to rotate the impeller 4l. Liquidfrom the pond P in the tank Il flows by gravity into the sump S and through the opening 43a of the throat ring 43 into the open ended chamber provided through the volute ring and impeller. The vanes 43 create a large volume axial ilow of liquid in an upward direction through the central chamber of the pump andv this liquid, as indicated by the arrows in Figure l, i.

is deflected by the shield Il downwardly toward the screen disk 4 3.

.The centrifugal pumping vanes 45 centrifugally discharge some of the liquid flowing axially through-the pump into the volute chamber 3l. Since this liquid is quite volatile and since the vanes 4l agitate the liquid, bubbles of gas and vapor are liberated from the liquid and, being lighter than the liquid, are not thrown radially outwardly into the volute chamber but collect along the inner ends of the vanes 4l to be entrained in the axial flow stream of liquid created by the vanes'43. Bubbles B thus flow upwardly, with the liquid issuing out of the top end of the impeller. to the deilector I4. The bubbles B being lighter than the liquid however, will rise through the pond P as soon as they clear the outer peripheral edge of the deflector 5S. Some bubbles might be entrained with the downwardly flowing liquid to the pump, as indicated in Figure l. but the screens 41 and 4l' prevent bubbles from being fed back to the pump for re-entry into the pump. The mesh of the sc reens is fine enough so that bubbles cannot pass therethrough.

Since the axialflow vanes 43 circulate more liquid through the pump than is circulated into the volute chamber by the centrifugal vanes 45, an excess of liquid is moved'locally in the pond P around the pump, and this liquid is recirculated back to the pump by the shield I8. Thus, volatile liquids such as gasoline are subjected to repeated agitation before being pumped into the fuel line and become stabilized since their volatiles, whichare about to gasify, are removed from the liquid in the form of liberated bubbles which rise through the tank and burst at the surface of the tank.

As a result, when an airplane flies to high alti tudes and volatiles in the vented fuel tank thereof become successively more unstable, the pump rating pump which recirculates liquid so that the liquid is repeatedly subjected to a vapor separating treatment before it is pumped, thus producing a stabilized, fully liquid material for pumping.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therei re, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention;

1. A pump for separating gases and liquids which comprises pumping vanes for centriiugally diseharging'liquids, means for circulating liquids through the pump along the pumping vanes to Iprevent the pumping varies from becoming gasbound, and a deflector spaced from said means in the path of liquids flow therefrom and cooperating with said means to recirculate the liquids back to the pumping varies.

2. A vapor-separating pump comprising means dening a volute chamber having a central inlet, and a central outlet, an impeller having pumping vanes for centrifugally impelling liquid from the inlet to the volute chamber together with ow vanes for flowing liquid from the inlet to the central outlet for sweeping liberated vapors away from the pumping vanes, and a deflector shield in spaced relation from said ow vanes for directing the liquid impelled thereby back to the central inlet.

3. A stabilizing pump which comprises a casing having a central inlet, an annular pumping chamber, and a central outlet, an impeller rotatably mounted in said casing having pumping vanes for discharging liquid from the inlet to the pumping chamber together with additional vanes for flowing liquid from the inlet to the central outlet for sweeping bubbles of vapors out of the pump, a deiiecto` shield mounted in the path of liquid discharged from the central outlet for deflecting said liquid back to the pump inlet, and a screen interposed between said shield and the pump inlet for preventing passage of bubbles therethrough.

4. In combination with a tank having an aper-YV tured bottom wall, a pump and motor unit in in said tank having a'base closing the aperture oi said tank wall and defining a sump for the tank, the pump of said Iunit having an openended vertical passageway above said sump withV a pumping chamber around the passageway in communication therewith intermediate the open ends thereof, the motor of said unit being spaced above the top end or said passageway, an umbrella-shaped deflector. between the motor land top end of the passageway arranged to deiiect liquids rising from the passageway back to the sump, a shaft depending from the motor and driven thereby, an impeller on the shaft having a ring of circumferentially spaced pumping vanes in the passageway arranged for pressuring liquids from the .passageway into the pumping chamber and for agitating the liquids to' liberate therefrom, said impeller `also having blades for flowing liquids through the passageway and out of the top end thereof to sweep the bubbles out of the pump toward the denector and a screen between the tank and sump having a mesh arranged forpreprising venting passage of bubbles in the deflected liquid back to the passageway.

5. Incombination, a tank, a pump in said tank having a free flow passage therethrough open 'at both ends to the interior of the tank, an agitating impeller rotatably mounted in the passage to centrifugally pump liquids therefrom and to liberate gases and vapors from the liquids, a. propeller for iiolwing large volumes of liquid from the tank through the passage and back to the tank to sweep out the bubbles of gas and vapor liberated by the impeller, and a defiector shield in the tank arranged for recirculating liquids in the tank `from the passage back to the passage to repeatedly treat the liquids before they are centrifugally pumped.

6. A submerged pump and motor unit comvertically spaced pump and motor casings, said pump casing being below the motor casing and having an open ended free flow passage therethrough and a pumping chamber therearound in communication with the passage, motor casing having a motor shaft extending therefrom, a pump impeller on the shaft in the passage having centrifugal pumping and agitating vanes for pressuring liquids from the passage into the pumping chamber and for liberating bubbles of gas and vapor from liquids' together with iiow vanes for owing liquid and occluded bubbles through the passage, and a deflector between the pump and motor casings arranged for recirculating liquids from the passage downwardly back to the passage while allowing bubbles in the liquid to rise above the deflector.

7. A vapor separating pump comprising a pump casing having a vertical passageway therethrough open at the top and bottom and a pumping chamber surrounding the passageway in annular communication therewith, agitating pumping varies in the passageway, and means for repeatedly circulating liquid through the passageway to pretreat the liquid before it is pumped.

8. A liquid stabilizing assembly which comprises a tank for containing a pool of liquid.' a pump in said tank having an inlet and an axial outlet communicating with a pool of liquid in the tank, said pump having a peripheral outlet communicating with the exterior of said tank, an impeller in said pump for discharging liquid from the inlet to the peripheral outlet, a. second impeller in said pump for flowing liquid from the inlet through the axial outlet back to said pool of liquid in the tank, and a deilector device in said tank spaced from said axial outlet in the path of liquidflow therefrom for recirculating liquid from the axial outlet back to the inlet.

9. A pump and tank assembly comprising a tank for a pond of liquid, a pump casing in said tank having a passageway communicating at both ends thereof with liquid in the tank, pumplng vanes in said casing for pressuring liquids from said passageway, flow vanes for circulating liquids and bubbles released, by the pumping vanes through the passageway out of the pump and back to the pond of liquid in the tank, and a defiector in said tank in the path of liquid flow from -the passageway to direct the thus circulated liquids back to the pump.

" THEODORE R. DINSMORE.

said 

